Patent US5254176A successfully refreshed from Google Patents.
US5254176A
Expired / Lapsed
US
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Method of cleaning a process tube
Assignee: Tokyo Electron Ltd
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Filing: 1992-02-03
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Granted: 1993-10-19
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Expires: 2012-02-03
Abstract
Abstract A method of cleaning the process tube of the CVD apparatus comprising carrying silicon wafers out of the process tube, making temperature in the process tube lower enough than the process temperature, that is, equal to or higher than room temperature, and supplying cleaning gas, in which ClF3 is contained, into the process tube to react with poly-silicon and amorphous silicon (Si) stuck to that portion of the inner wall of the process tube which is not in the uniformly-heated zone in the process tube, whereby the matters stuck can be removed from the inner wall of the process tube for a shorter time.
Inventors
- 👤 Shigehito Ibuka
- 👤 Chitoshi Nogami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:04
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0406; C; C03; C03C; C03C23/00; C03C23/0075; C23; C23C; C23C16/00; C23C16/44; C23C16/4401; C23C16/4405
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
118 words
A cleaning method for removing a low density silicon-based film adhered to an inner wall of a ceramic process tube in a process of forming a silicon-based film on a semiconductor wafer, comprising the steps of: taking a wafer having a silicon-based film formed thereon out of said process tube; then controlling the temperature within the process tube to fall within a range of between 400° C. and the boiling point of ClF 3 ; supplying, while the temperature is controlled to be below 400° C., a cleaning gas containing ClF 3 into the process tube to allow said cleaning gas to react with said low density silicon-based film; and releasing the gaseous material from the process tube.
Claim 2
Dependent Claim
118 words
A cleaning method for removing a low density silicon-based film adhered to an inner wall of a ceramic process tube in a process of forming a silicon-based film on a semiconductor wafer, comprising the steps of: taking a wafer having a silicon-based film formed thereon out of said process tube; then controlling the temperature within the process tube to fall within a range of between 400° C. and the boiling point of ClF 3 ; supplying, while the temperature is controlled to be below 400° C., a cleaning gas containing ClF 3 into the process tube to allow said cleaning gas to react with said low density silicon-based film; and releasing the gaseous material from the process tube.
Claim 3
Dependent Claim
66 words
A method according to claim 1, further comprising: supplying said cleaning gas in the process tube and making internal pressure in the process tube negative while exhausting the process tube through an exhaust means; and reacting said cleaning gas with mono-crystal-silicon, poly-crystal-silicon and/or amorphous silicon which have/has adhered, during the SiO 2 film forming process, to the inner wall of zones, other than uniformly heated zone.
Claim 4
Dependent Claim
20 words
The method according to claim 2, wherein a dry pump of the oil-free type is used as the exhaust means.
Claim 5
Dependent Claim
37 words
The method according to claim 1, wherein a heating power supply is switched off to lower the temperature in the process tube substantially to room temperature and the cleaning gas is then supplied into the process tube.
Claim 6
Dependent Claim
25 words
The method according to claim 1, wherein the cleaning gas includes at least one of oxygen gas, nitrogen gas, argon gas and CF 4 gas.
Claim 7
Dependent Claim
14 words
The method according to claim 1, wherein the process tube is made of quartz.
Claim 8
Dependent Claim
14 words
A method according to claim 1, wherein the process tube walls comprise silicon dioxide.
Claim 9
Dependent Claim
24 words
A method according to claim 1, further comprising the step of: ultrasonically vibrating the process tube while ClF 3 is inside the process tube.
Claim 10
Dependent Claim
17 words
A method according to claim 8, wherein ultrasonically vibrating further comprises applying strong and weak ultrasonic waves.
Claim 11
Independent Claim
120 words
A method of heat-treating a semiconductor wafer within a process tube, comprising the steps of: forming a silicon-based film on a semiconductor wafer and taking said wafer having a silicon-based film formed thereon out of said process tube; then controlling the temperature within the process tube to fall within a range of between 400° C. and the boiling point of ClF 3 ; supplying, while the temperature is controlled to be below 400° C., a cleaning gas containing ClF 3 into the process tube to allow said cleaning gas to react with a low density silicon-based film adhered to said process tube during formation of the silicon-based film on said wafer; and releasing the gaseous material from the process tube.
Claim 12
Independent Claim
120 words
A method of heat-treating a semiconductor wafer within a process tube, comprising the steps of: forming a silicon-based film on a semiconductor wafer and taking said wafer having a silicon-based film formed thereon out of said process tube; then controlling the temperature within the process tube to fall within a range of between 400° C. and the boiling point of ClF 3 ; supplying, while the temperature is controlled to be below 400° C., a cleaning gas containing ClF 3 into the process tube to allow said cleaning gas to react with a low density silicon-based film adhered to said process tube during formation of the silicon-based film on said wafer; and releasing the gaseous material from the process tube.
Claim 13
Dependent Claim
41 words
The method according to claim 1 or 10, wherein the inner pressure of the process tube is controlled to fall within a range of between 0.1 to 2 Torr in the step of supplying said cleaning gas into said process tube.
Claim 14
Dependent Claim
55 words
The method according to claim 1 or 10, further comprising the step of calculating a cumulative operating time of said process tube before the step of controlling the temperature within the process tube, said cleaning gas being supplied to the process tube when the cumulative operating time has been found to exceed a certain value.
Claim 15
Dependent Claim
26 words
The method according to claim 10, wherein a film-forming treatment is applied within said process tube to a plurality of wafers supported by a boat means.
Claim 16
Dependent Claim
46 words
The method according to claim 1 or 10, further comprising the step of transferring a wafer support member supporting wafers within said process tube into the process tube before the step of taking the wafer having a film-forming treatment applied thereto out of the process tube.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1996-10-18 | 1997-04-19 | 1997-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-18 | 2001-04-19 | 2001-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-18 | 2005-04-19 | 2005-10-19 | $7700.00 | Window Closed / Lapsed |